Conventionally, axial fans and centrifugal fans used for cooling electric devices are driven by electrically powered motors. Such a motor includes a rotor unit having a rotor magnet around a center axis of the motor and a stator unit having a stator generating torque between the rotor unit and the stator unit. The stator unit includes a plurality of coils formed by winding wires around a plurality of teeth. The ends of the wires wound around the teeth are electrically connected to a circuit board such that the electricity is provided to the stator.
There are various methods of connecting the ends of the wires forming the coils and the circuit board. In a publicly available example of such method, firstly, a conductive pin axially protruding from the bottom side of the stator toward the circuit board is provided. Then, after twining the wire to the pin at below the stator, the pin is inserted into the bore provided on the circuit board and soldered.
Recently, the electronic devices are designed so as to miniaturize their dimensions, and the demands for small cooling fans have been rising. In such a small motor, the space between the pin to which the wire is twined and such as the stator core, the coil and the circuit board is so narrow that the needle of the wire-winding machine can not be easily placed therebetween. Therefore, it is difficult to mechanize (automate) the twining process of the wire.
In addition, the wires used for the small motor have so small diameters that they may cut during the process of attaching the wires to the circuit board. For example, in the motor using the conductive pin as mentioned above, the wire may cut, during the process of inserting the pin, to which the wire is twined, into the bore provided on the circuit board, by scratching the wire with the edge of the bore.